Tuesday, June 15, 2010

I'm a runner but I'm actually a teacher by profession. And I'm excited to sort of combine these two in my discussion later of this problem on uniform rectilinear motion and uniformly accelerated motion. [Oops sorry, the geek in me is out of control :P]

"A sprinter in a 400-m race accelerates uniformly for the first 130m and then runs with constant velocity. If the sprinter's time for the first 130m is 25s, determine (a) his acceleration, (b) his final velocity, and (c) his time for the race." [11.39, Vector Mechanics by Beer, Johnston, and Clausen, 8th].

Wow, that's 400m in 51 seconds! If he can keep that for 5k, then he'll be finished in less than 11 minutes! :))

I wonder if that's how fast runners really do their short runs - accelerating from rest to a very fast pace (this imaginary guy is over 30 kph) and then maintaining that speed. Makes me want to experiment on this one time around the oval. :P